JK: In the mid 60s, you also did some quite minimal work.

KB: These two paintings from 1964 were in the 1965 MOMA exhibition, The Responsive Eye. They are the most simplified of a series based on the relationship between a circle and a square.

#26, 1964, oil on canvas, 130 x 97 cm (51 x 38 in), 1964	#27, 1964, oil on canvas, 130 x 97 cm (51 x 38 in), 1964

JK: Subsequently, you produced a large series based on letters of the alphabet.

KB: A number of artists were using letters in their paintings around this time—Robert Indiana, Jasper Johns and others. Initially, I made small color sketches of each letter in block form on a field. In my paintings, I often used two letters side by side, as in the back-to-back Js below. Or I would overlap letters, then move one around to enhance the composition.

#13,1964, oil on canvas, 107 x 107 cm (42 x 42 in), 1964	#1, 1965, oil on canvas, 76 x 76 cm (30 x 30 in), 1965

Then some diagonals started creeping in, incidentally creating some 3-D box-like forms. Or I would use a larger number of different colors.

#8, 1965, oil on canvas, 107 x 107 cm (42 x 42 in), 1965	#24, 1965, oil on canvas, 107 x 107 cm (42 x 42 in), 1965

JK: In this more complex composition below, we see a central yellow H and two center-facing Es arranged like bookends.

#9, 1965, oil on canvas, 65 x 131 cm (25 1/2 x 51 1/2 in), 1965

In your next series, you began adding important new elements in your approach to composition making.

KB: Yes. The painting below was part of the first series of patterned works I made that were composed of triangles and based on a grid. Here I composed the left half of the painting, then rotated it 180º to generate the right half.

#9, 1966, oil on canvas, 66 x 130 cm (26 x 51 in), 1966

The overall design you get with this method of composing is out of your hands. But this method should not to be confused with randomness. There are a lot of conscious moves you make, but when you arrive at the module you’re using, rules come into play—here the rotation. It’s a way of letting go.

JK: You explored a variety of strategies to generate these patterned paintings. For example, in #4, 1967, the squares that form the top horizontal row are rotated 180º and form the bottom row. The second row from the top is rotated in the same way to form the second row up from the bottom, and so on.

KB: Yes. And the color in these two is quite lyrical, with many hues and tonal relationships.

#4, 1967, oil on canvas, 107 x 150 cm (42 x 59 in), 1967

In some of these paintings, like #9, 1969 below, I used fewer colors, and the module is only 3 squares high by 3 squares wide.

#9, 1969, oil on canvas, 173 x 173 cm (68 x 68 in), 1969

JK: And once again, you used a simple motif to generate paintings of great visual variety.

#19, 1967, oil on canvas, 127 x 127 cm (50 x 50 in), 1967	#7, 1968, oil on canvas, 128 x 128 cm (50.5 x 50.5 in), 1968

KB: After the final color went down and I removed the tape to reveal the completed painting, I would always be rewarded with a delightful sense of surprise.

#2, 1970, oil on canvas, 173 x 173 cm (68 x 68 in), 1970	#8, 1970, oil on canvas, 173 x 173 cm (68 x 68 in), 1970

I wanted to introduce a little air into these painting. To do this, I began with a square module composed of smaller squares, and I cut the module in half on the diagonal. The rule in arranging the resulting triangular modules was that no module could overlap another and each had to fit completely on the canvas. As can be seen in #10, 1971, areas of the white field color were also included within the modules, increasing the variety of the resulting forms.

#10, 1971, oil on canvas, 173 x 173 cm (68 x 68 in), 1971

JK: The arrangement of these modules produced strikingly different compositions even when the colors used were the same among paintings.

#14, 1971, oil on canvas, 127 x 127 cm (50 x 50 in), 1971	#6, 1971, oil on canvas, 173 x 173 cm (68 x 68 in), 1971

KB: Whatever the system or strategy I used, I always selected the colors and the overall schema or method. You begin with something you feel is beautifully designed, but you can’t completely forsee the overall wholeness of the work until it is completed.

JK: In the early 70s, you produced a series composed of many small rectangles arranged in precise grids.

#4, 1972, oil on canvas, 130 x 173 cm (51 x 68 in), 1972

KB: In these paintings, I would choose a number of colors—sometimes 24 different colors, sometimes eight colors with three variations on each. I’d make a ticket for each one, put them in a container, and have my daughter, Kris, pick colors one by one, returning each to the container after selecting it. The only rule was that the same color could not be used side by side as this would have introduced a different type of form.

JK: So you allowed chance to play an important role in the composition of these paintings.

KB: Yes. Interestingly, in a recent New Yorker article on the stained glass windows of Gerhard Richter and Sigmar Polke, Richter commented that chance is “more clever than I.” (“Many-Colored Glass” by Peter Schjeldahl, The New Yorker, May 12, 2008)

The painting below is unique in this series. It was inspired by how color was affected as light was refracted through partially overlapping panes of glass in a sliding glass window in my studio.

#8, 1972, oil on canvas, 122 x 163 cm (48 x 64 in), 1972

In the painting below, I once again felt the need for some air in the work. Here, instead of 24 colors I only used 12, with the remaining rectangles all an identical field color.

#6, 1974, oil on canvas, 130 x 173 cm (51 x 68 in), 1974

JK: After these more complex gridded works, you once again greatly reduced the number of shapes in a given painting.

KB: Yes, but here I added diagonals, which created some spatial ambiguity.

#7, 1974, oil on canvas, 102 x 102 cm (40 x 40 in), 1974	#10, 1974, oil on canvas, 122 x 122 cm (48 x 48 in), 1974

These forms could be seen as advancing or receding; they could have a three-dimensional effect despite the fact that when I painted them, I was thinking flatness—diagonals and the flatness of the canvas, which you can’t help but be aware of.

#7, 1973, oil on canvas, 81 x 81 cm (32 x 32 in), 1973	#19, 1975, oil on canvas, 142 x 142 cm (56 x 56 in), 1975

Then I made several series of stripe paintings. In #21, 1975, I was thinking both of vertical forms and the designed shapes of the background. In retrospect, I see a continuing simplification in the stripe series until those of the 80s, which had maximum optical effects.

#21, 1975, oil on canvas, 150 x 75 cm (59 x 29 1/2 in), 1975

JK: You did a number of paintings composed of 1/2″ wide stripes set at 1″ intervals.

#7, 1976, oil on canvas, 157 x 79 cm (62 x 31 in), 1976	#8, 1976, oil on canvas, 157 x 79 cm (62 x 31 in), 1976

KB: The two paintings above were from a series of four, each with four bands of stripes against a uniform field color. But you still had to stand back a ways to appreciate the optical effects.

#13, 1977, oil on canvas, 144 144 cm (56 1/2 x 56 1/2 in), 1977

I always made color choices that felt right to me. I wasn’t trying to achieve maximal optical bounce; it wasn’t a case of making mechanical choices in terms of which color would vibrate the most against another—a machine could have worked that out better.

#14, 1977, oil on canvas, 127 x 184 cm (50 x 72.5 in), 1977

JK: After making some stripe paintings where every interval was 1/2″ wide, you next did a large series of tall vertical stripe paintings where the stripes were all 1/4″ wide, and the optical mixing was intense, even from quite close up.

#8, 1980,oil on canvas, 183 x 122 cm (72 x 48 in), 1980	#8, 1980 detail

In the early 80s, you also made quite a different series using stripes—this time composed of thick horizontal stripes and involving sequences of color gradations.

KB: The paintings in this Three Mile Island group had a certain sense of atmoshere. I felt they were almost like atomic explosions at different times of day or night.

#3, 1983, oil on canvas, 160 x 114 cm (63 x 45 in), 1983	#10, 1982, oil on canvas, 160 x 114 cm (63 x 45 in), 1982

JK: In the late 70s, you did another rectangle-based series.

KB: These Cloud paintings were quite different from anything I’d done before. At first I didn’t realize the central shapes resembled clouds against a sky seen at different times of day or night with small triangles of sunlight or moonlight peeking through. #4 suggets clouds at midday, and #14 resembles a sunset on a hot, smoggy day in late summer. At that time, you can sometimes really see turquoise among the clouds.

#4, 1979, oil on canvas, 122 x 160 cm (48 x 63 in), 1979	#14, 1979, oil on canvas, 122 x 160 cm (48 x 63 in), 1979